Trialkyl Phosphite Transesterification with Alkaline Catalyst

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current methods for producing trialkyl phosphites with ultra-low phenol content are inefficient, environmentally unfriendly, and result in unstable products with high residual phenol levels, posing health risks in enclosed spaces and generating significant waste due to the use of solvents and toxic by-products.

Innovation Solution

A transesterification method using an alkaline catalyst like potassium fluoride under anhydrous conditions and inert gas atmosphere, where triaryl phosphites react with aliphatic alcohols to produce trialkyl phosphites with less than 0.01 wt% free phenol and 0.1 wt% total phenol, eliminating the need for solvents and reducing by-product formation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If esterification of phosphorus trichloride with alcohol is used to obtain ultra-low phenol trialkyl phosphites, then phenol content is reduced to near zero, but the process generates large amounts of hydrogen chloride requiring neutralization with tertiary amines, creating solid amine hydrochloride by-products that require solvent for dissolution and subsequent extraction steps

Engineering Contradiction:

Improvephenol contentVSAvoidsolvent consumption and by-product generation

Core Design Contradiction:

Object-affected harmful factorsVSLoss of substance

Solution Approach 1:

The invention extracts and removes the problematic phenol-containing by-products from the reaction system through distillation, separating them from the desired trialkyl phosphite product. This allows the reaction to proceed without requiring large amounts of solvent for by-product management, as the phenol is continuously removed from the system.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention changes the reaction parameters by using a different esterification approach that operates under conditions where phenol by-products can be easily distilled off. The process uses excess alcohol as reactant and employs controlled temperature and pressure conditions to facilitate phenol removal while maintaining product stability.

Inventive Principle:

Principle #35Parameter changes

2Object-affected harmful factors

If tertiary amines are used to neutralize hydrogen chloride in phosphite synthesis, then phenol content is reduced, but equal molar volumes of toxic hydrogen chloride acceptor create very large amounts of undesired by-product requiring complex recycling

Engineering Contradiction:

Improvephenol contentVSAvoidprocess complexity and by-product recycling

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The invention converts the harmful phenol by-product into a beneficial situation by using it as an indicator for reaction completion and as a removable component that drives the equilibrium forward. The phenol is continuously distilled off, preventing it from contaminating the final product while simplifying the overall process by eliminating the need for complex amine hydrochloride recycling systems.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Object-affected harmful factors

If transesterification method is used to obtain ultra-low phenol content trialkyl phosphites, then phenol content is reduced and yields are improved, but product stability over time is unsatisfactory

Engineering Contradiction:

Improvephenol contentVSAvoidproduct stability

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The invention performs preliminary purification of the trialkyl phosphite product by distilling off phenol-containing by-products during the reaction process itself, before the product is isolated. This preliminary removal of unstable phenolic components ensures the final product has both ultra-low phenol content and improved long-term stability.

Inventive Principle:

Principle #10Preliminary action

4Object-affected harmful factors

If phenol content in phosphite stabilisers is reduced to meet strict requirements for enclosed spaces, then health safety is improved, but the use of conventional methods generates significant waste and environmental pollution

Engineering Contradiction:

Improvephenol contentVSAvoidwaste generation and environmental impact

Core Design Contradiction:

Object-affected harmful factorsVSObject-generated harmful factors

Solution Approach 1:

The invention makes the reaction system self-servicing by using the phenol by-product as a driving force for the reaction equilibrium. The continuous distillation of phenol automatically shifts the equilibrium toward product formation without requiring external intervention or additional reagents, thereby reducing waste generation while achieving ultra-low phenol content in the final product.

Inventive Principle:

Principle #25Self-service

Data Source

PatentEP4458831A1Method of transesterification of phosphites to obtain a product with ultra-low phenol content

Publication Date: 2024.11.06 PCC ROKITA SPOLKA AKCYJNA

AI summary

The invention relates to a method of transesterification of phosphites using alcohol in the presence of a fluoride alkaline catalyst allowing to obtain liquid organic phosphites with ultra-low phenol content and low volatility. Trialkyl phosphites obtainable by the method of the present invention, are used e.g. as additives to lubricants or as auxiliary stabilisers in the processing of various plastics, including those based on polyurethane and poly(vinyl chloride).